From patchwork Mon Dec 18 10:41:04 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Atish Kumar Patra X-Patchwork-Id: 13496547 Received: from mail-oo1-f45.google.com (mail-oo1-f45.google.com [209.85.161.45]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 6AE911C283 for ; Mon, 18 Dec 2023 10:41:29 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=rivosinc.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=rivosinc.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=rivosinc-com.20230601.gappssmtp.com header.i=@rivosinc-com.20230601.gappssmtp.com header.b="nCa27SLn" Received: by mail-oo1-f45.google.com with SMTP id 006d021491bc7-5913922ab10so1848481eaf.1 for ; Mon, 18 Dec 2023 02:41:29 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=rivosinc-com.20230601.gappssmtp.com; s=20230601; t=1702896088; x=1703500888; darn=vger.kernel.org; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:from:to:cc:subject:date :message-id:reply-to; bh=h9sAaI5x/m4qa/IsblGkrHPvGq73TiWdoovLssK6KVs=; b=nCa27SLn2DNBvk+Chcy2MP96Ube2n3Wt2sQ5kgdW2KARzmN+sj3lq0cEaxUpdre86M h7+wU4Thtb4YF/9jMtlBXt3SdOKT1CghRlbwLv5p2/5nC6TyxjL2zH6neFsSIT/Bhjwg hc3I8SLkggHIK+ja53kfQlmxg7hzJkaqw98Zc0cv7E0zme+3H5Q4U3UeX5dYar+aFmkN DWC/U3Z6NW6OuXqxoTIL3gYo86mdWf4s0NUsl72JcBebrsaUCA9yxzsLKy4vGztQ5N2z O6IBQXdG+8gy6g9iYyRMT3Zb+gtjXOTAl6D1XV8IGx5BpY4BOs8afxJzG+gzlfoepxtW 59OA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1702896088; x=1703500888; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=h9sAaI5x/m4qa/IsblGkrHPvGq73TiWdoovLssK6KVs=; b=VySk/MYV7qhsiQtteKM87DpoIHERrvem0HdmYXiKGQ4lEq5vFT21L4lCw5EKAm4DjO JABOEdr24H1aNi2q99wfJm+GwI3kC211UVO0uK5A6PNMrKYjdbD9JpZhGGnFhOyYIbQ0 HGZ4us1Z4CIVHYM7rlgVkFMeYw57rWEb1lZQ7ikD3PbeY5+vdUWHGSbdRrBPCzwjetgo wvrEmZPYZgtSvanmTC+VKv3dDraYA8EgODRLZgCkuSjISblJE4zUXwBu6b+HPOclPz85 ftjaeVYB/kPS6725FaR2XFnKQsEaSxxy001X95gFVhbZZBl2Vnr8BTkUZ+JZILvDlJ1E 5O/g== X-Gm-Message-State: AOJu0YzkdKHsEqEh2KVpIp+YpnM1ocoDpk0km+FSBGna9CwyH7Zsz8P+ 3NhRUpCBbwZH30TWjYKsbwjXTg== X-Google-Smtp-Source: AGHT+IE8rqcGYbpX5zfzh086GD+kPOXZmg7tTADIINBhCIkcHBriRp6Yc5OpCWAefeUGFA0vrx+W3g== X-Received: by 2002:a05:6820:168b:b0:58e:1c47:6321 with SMTP id bc11-20020a056820168b00b0058e1c476321mr10764799oob.15.1702896088517; Mon, 18 Dec 2023 02:41:28 -0800 (PST) Received: from atishp.ba.rivosinc.com ([64.71.180.162]) by smtp.gmail.com with ESMTPSA id 185-20020a4a1ac2000000b005907ad9f302sm574970oof.37.2023.12.18.02.41.27 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 18 Dec 2023 02:41:28 -0800 (PST) From: Atish Patra To: linux-kernel@vger.kernel.org Cc: Atish Patra , Albert Ou , Alexandre Ghiti , Andrew Jones , Anup Patel , Atish Patra , Conor Dooley , Guo Ren , Icenowy Zheng , kvm-riscv@lists.infradead.org, kvm@vger.kernel.org, linux-riscv@lists.infradead.org, Mark Rutland , Palmer Dabbelt , Paul Walmsley , Will Deacon Subject: [v1 07/10] RISC-V: KVM: No need to exit to the user space if perf event failed Date: Mon, 18 Dec 2023 02:41:04 -0800 Message-Id: <20231218104107.2976925-8-atishp@rivosinc.com> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20231218104107.2976925-1-atishp@rivosinc.com> References: <20231218104107.2976925-1-atishp@rivosinc.com> Precedence: bulk X-Mailing-List: kvm@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Currently, we return a linux error code if creating a perf event failed in kvm. That shouldn't be necessary as guest can continue to operate without perf profiling or profiling with firmware counters. Return appropriate SBI error code to indicate that PMU configuration failed. An error message in kvm already describes the reason for failure. Fixes: 0cb74b65d2e5 ("RISC-V: KVM: Implement perf support without sampling") Signed-off-by: Atish Patra --- arch/riscv/kvm/vcpu_pmu.c | 14 +++++++++----- arch/riscv/kvm/vcpu_sbi_pmu.c | 6 +++--- 2 files changed, 12 insertions(+), 8 deletions(-) diff --git a/arch/riscv/kvm/vcpu_pmu.c b/arch/riscv/kvm/vcpu_pmu.c index 8c44f26e754d..08f561998611 100644 --- a/arch/riscv/kvm/vcpu_pmu.c +++ b/arch/riscv/kvm/vcpu_pmu.c @@ -229,8 +229,9 @@ static int kvm_pmu_validate_counter_mask(struct kvm_pmu *kvpmu, unsigned long ct return 0; } -static int kvm_pmu_create_perf_event(struct kvm_pmc *pmc, struct perf_event_attr *attr, - unsigned long flags, unsigned long eidx, unsigned long evtdata) +static long kvm_pmu_create_perf_event(struct kvm_pmc *pmc, struct perf_event_attr *attr, + unsigned long flags, unsigned long eidx, + unsigned long evtdata) { struct perf_event *event; @@ -455,7 +456,8 @@ int kvm_riscv_vcpu_pmu_ctr_cfg_match(struct kvm_vcpu *vcpu, unsigned long ctr_ba unsigned long eidx, u64 evtdata, struct kvm_vcpu_sbi_return *retdata) { - int ctr_idx, ret, sbiret = 0; + int ctr_idx, sbiret = 0; + long ret; bool is_fevent; unsigned long event_code; u32 etype = kvm_pmu_get_perf_event_type(eidx); @@ -514,8 +516,10 @@ int kvm_riscv_vcpu_pmu_ctr_cfg_match(struct kvm_vcpu *vcpu, unsigned long ctr_ba kvpmu->fw_event[event_code].started = true; } else { ret = kvm_pmu_create_perf_event(pmc, &attr, flags, eidx, evtdata); - if (ret) - return ret; + if (ret) { + sbiret = SBI_ERR_NOT_SUPPORTED; + goto out; + } } set_bit(ctr_idx, kvpmu->pmc_in_use); diff --git a/arch/riscv/kvm/vcpu_sbi_pmu.c b/arch/riscv/kvm/vcpu_sbi_pmu.c index 7eca72df2cbd..b70179e9e875 100644 --- a/arch/riscv/kvm/vcpu_sbi_pmu.c +++ b/arch/riscv/kvm/vcpu_sbi_pmu.c @@ -42,9 +42,9 @@ static int kvm_sbi_ext_pmu_handler(struct kvm_vcpu *vcpu, struct kvm_run *run, #endif /* * This can fail if perf core framework fails to create an event. - * Forward the error to userspace because it's an error which - * happened within the host kernel. The other option would be - * to convert to an SBI error and forward to the guest. + * No need to forward the error to userspace and exit the guest + * operation can continue without profiling. Forward the + * appropriate SBI error to the guest. */ ret = kvm_riscv_vcpu_pmu_ctr_cfg_match(vcpu, cp->a0, cp->a1, cp->a2, cp->a3, temp, retdata);